1. Field of the Invention
The present invention generally relates to a set of software objects that represent, store, and dynamically retrieve information on behalf of user applications, thereby facilitating the implementation of information systems. These software objects model the structural properties of information, independently of semantics.
2. Description of the Related Art
Information systems where agents, human or artificial, interact with interconnected information resources are called “distributed knowledge environments.” These systems are the emerging information model of networks, ranging from digital library systems to the Internet and multi-agent cooperative environments. The information resources typically are databases that function as passive file cabinets.
Agents must know the structure of the filing system in order to use it. That is, they must know which cabinet (table or view) contains the data they wish to access and must know or deduce why the data was stored there. For example, to access a database on real estate data, a human real estate agent must know that a table House contains the city and price of houses, and that houses are located in cities, and have prices.
This example is trivial enough. However, when data belongs to a specialized domain or when it needs to be discovered, as often happens in distributed systems, agents do not know the details of the data organization in advance. Also, different agents view and organize data in different ways. For example, a human agent who is a tax attorney might view houses as taxable properties, while a human agent who is a prospective buyer might be more interested in houses as habitation units having attributes such as bedrooms, bathrooms, etc.
Building these open-ended information environments is a daunting task. For example, how can data be modeled when it is not known how it is going to be used? Additionally, how can a human or software agent access data having an organization that is not known in advance? These questions are important to support intelligent agent systems where agents can evolve and share knowledge.
Therefore, there remains an unsolved challenge to model and use information in a systematic, domain-independent manner.
Even though a lot of work has been done in network information systems, such as semantic network and frame systems (KL-One family, like Classic or LOOM), there currently exists no low-level information network that can represent contexts and data views flexibly to meet the requirements above.